Identification arrangement



1967 J. KOORNEEF ETAL 3,303,496

IDENTIFICATION ARRANGEMENT Filed se t.,so, 1964 2 Sheets-Sheet 1BISTABLE TRIGGER AE I/AERIAL FREQUENCY GATE ZERO sET UIv pE I; .ZERO SET'1 f m 0 P5 TRANSMITTER 5D PULSE BE COUNTING COUNTING CIRCUIT f CIRCUITCOUNTING l A CIRCUIT icATcicefTIa Bc COINCIDENCE cIRCUITs LIMITINGRECEIVING RECEIVER c AERIAL- SC BISTABLE TRIGGERS FC U BX E lkfigmg N- IRATIN 5M2! -BA 1 DELAY BB 'BH I VR II 1 LI m RECEIVING MG RECEIVER 5N PNAERIAL I 1 V I [-4- E -SHIFT REGISTER I I /BK CC I FIG? COINCIDENCECIRCUIT INVENTORS JACOB KOORNEEF JACOBUS M. DEN HERTDG BY f A e PIII/70M.

Feb. 7, 1967 J. KOORNEEF ETAL 3,303,496

IDENT IFI CAT ION ARRANGEMENT Filed Sept. 50, 1964 2 Sheets-Sheet 2RECEIVING AERIAL I V CODE D|SC' READING HEAD RE GA csiFiGfic|||n1munlmuuluumluuunmmummummllmumlmlmmllllllllllllllllllllllllllllllllllllllll INVENTORj JACOB KOORNEEF?JACOBUS M. DEN HERTOG B M 6. ,qain r' United States Patent ()fifice3,3@3,4% Patented Feb. 7, 1967 3,303,496 IDENTIFICATION ARRANGEMENTJacob Koorneef and Jacobus Marius den Hertog, Em-

masingel, Eindhoven, Netherlands, assignors to North American PhilipsCompany, Inc., New York, N.Y., a corporation of Delaware Filed Sept. 30,1964, Ser. No. 400,473 Claims priority, application Netherlands, Oct. 2,1963, 298,733 5 Claims. (Cl. 343-65) The invention relates to anarrangement for identifying articles, for example railway carriages orarticles on a conveyor belt, movable with respect to a testing device.

The requirements which must be imposed in practice 'on an arrangementfor identifying railway carriages are particularly stringent. Since agreat amount of data is desired, the information supplied must consistof a code number of ten or more decimal digits. Each digit or each digitgroup has a given meaning and characterizes, for example, the country oforigin, the stand, the number of the carriage, and so on. It must bepossible to carry out identification at a low speed or standstill of thetrain and also at a speed of, for example, 160 kms. per hour, in whichlatter case the time available for the identification is very short.Neither the so-called buffering of the carriages, which cause thesecarriages to perform a reciprocating movement, nor the direction ofmovement of the train must exert any influence. For reasons of safety,the distance between the testing device and the train may not be smallerthan, for example, 40 cms., while on the other hand, also in connectionwith the different widths of the carriages, the distance may even be 90cms. As a matter of course, the arrangement must operate reliably underall conditions, including snow or glazed frost. Moreover, itis desirablethat the identification apparatus on the carriages have small dimensionsand be accommodated, for example, in a cabinet of 20 cms. x 20 cms. x 5cms. Another particularly stringent requirement is that it is notpossible to use energy sources on the train such as accumulators,dynamos driven by the wheels, traction energy and so on. Prior systemsutilize one or more oscillators on the carriages which are fed by energytransmitted radiographically by the testing device along the track tothe identification apparatus on the carriages and which send a signal bywireless transmission back to the testing device. This signal ismodulated in a manner characterizing the carriages. More particularly,these known arrangements operate electronically and the oscillators aremodulated with a multifrequency code. However, this requires a pluralityof auxiliary generators for producing the various modulationfrequencies, electronic switches and so on, the identification apparatuson each carriage comprising a comparatively large number of transistorsand hence is expensive. Moreover, the energy consumption of thesearrangements is comparatively high due to the large number oftransistors, so that the quantity of energy received by radiation mustalso be very large.

The invention provides a particularly simple and relatively inexpensivesolution to the problem.

The identification arrangement, in accordance with the invention,provides a small motor driven by energy transmitted from the testingdevice to the article to be identified. The motor brings about areciprocating movement between a code carrier and a reading memberwhereby a sequence of pulses characterizing the article is produced. Thesequence of pulses comprises at least one characteristic code groupmarking the beginning of the code series and a series of synchronizingpulses, synchronous with this reading process which mark the beginningof each code group. The code series modulates at least one oscillatorfor the wireless transmission of this information to the testing device.

Since the time available for the identification may be short,identification must be complete before the motor has reached its nominalnumber of revolutions, in other words, the testing device receives apulse code series having a variable signalling speed. this pulse codeseries to be decoded in a correct manner, according to a further featureof the invention, the testing device comprises means for producingduring each period between two synchronizing pulses a quantitycharacterizing the duration of this period, while the following periodis divided into a number of subperiods proportional to the number ofelements of each pulse code group for the formation of reading markpulses for determining the polarity of the received signals.

The invention will now be described more fully, with reference to theaccompanying drawing which shows an embodiment of an arrangement foridentifying railway carriages.

FIG. 1 shows diagrammatically part of a testing device arranged at afixed point along the railway track, and FIG. 2 shows an identificationapparatus arranged on the carriages.

FIG. 3 illustrates an embodiment of a code disc, while FIGS. 4a-4drelates to a pulse-time diagram.

The testing device shown in FIG. 1 comprises an auxiliary interrogatortransmitter ZE which is capable of transmitting energy having afrequency of, for example, 20 kc./s., through an aerial AE to areceiving aerial RE (FIG. 2) on a passing carriage tuned to thisfrequency by means of a capacitor KA. The aerial AB is, for example, aframe aerial of elongated shape, for example of 1 m. x 3 ms., while theaerial RE is, for example, a frame aerial of 15 cms. X 15 cms., so thatalso with a train passing at high speed, the aerial RE lies inside thefield of radiation of the aerial AE for a sufficiently long time. As amatter of course, the generator ZE need only be switched into circuitwhen a train or a carriage passes.

The energy absorbed by the aerial RE of the arrangement shown in FIG. 2is rectified by a rectifier GA so that a direct voltage V is producedacross a smoothing capacitor KB, which voltage drives on the one handthe motor M, while it feeds on the other hand the transmitters ZC andZN. The total quantity of energy absorbed is, for example, of the orderof 250 mw., and is approximately completely consumed by the motor duringits start. The nominal rotational speed of the motor is, for example, 25revolutions per sec. and half this speed is attained, for example, in 40milliseconds. When the motor has reached its nominal speed, theconsumption is, for example, only 10 mw.

The motor M drives a code disc CS provided with a teeth characterizingthe article and with holes AP, as shown in FIG. 3. The teeth and theholes move along reading heads KN and KC which consist of a winding on apermanently pre-magnetized magnetic circuit having an air gap. The teethand the holes vary the magnetic resistance of the circuit so that thereading heads supply pulses, as shown in FIG. 4a and in FIG. 4b.

The voltage produced by the reading heads is proportional to thevariation of the magnetic flux per unit time, hence proportional to thespeed of variation of the magnetic flux. In order to ensure that theoutput pulses of the reading heads have a fairly rectangular shape, theteeth are shaped into the form of a saw-tooth having an oblique edge anda straight edge. The code disc CS as shown in FIG. 3 is designed for acode of eight code groups of five elements each, that is to say astarting code group SC of five mark elements (teeth) and seven identifi-In order to permitv a cation digits C1, C2 C7 constituted by a2-out-of-5 code, that is to say that each code .group has two markelements (teeth) and three space elements. For example, the first digitC1 consists of a space element, two mark elements and two spaceelements; the second digit C2 of two space elements, one mark element,one space element and one mark element, and so on. The holes AP arelocated at the beginning of each code group so that the synchronizingpulses supplied by the reading head KC mark the beginnings of thesuccessive code groups.

FIG. 4a shows the series of pulses supplied by the reading head KN uponrotation of the code disc, and

FIG. 4b shows the synchronizing pulses of the head KC. By the exchangeof the code disc, the code may be varied in a simple manner. A new codedisc can be manu factured rapidly with the aid of a suitable punchingvice. In practice, the number of digits required for the identificationof a carriage will generally exceed 7 and be for example, from 12 to 15.These digits characterize, for example, the country of origin, thenormal stand, the number of the carriage, and so on. In general, such acode is invariably associated with a given carriage and needconsequently not be varied. However, it may be desirable in practice tohave part of the code variable, for example, the part characterizing theplace of destination of the priority in accordance with the load, forexample, in case of deep-frozen goods. In such cases, it is preferablefor the code disc to be fixedly arranged and for the reading heads to becaused to move along this disc under the control of the motor. Thevariable part of the code may then be adjusted by means of slides andthe like.

The pulse series produced by the reading heads KC and KN are supplied totwo transmitters ZC and ZN, respectively, which are designed in acorresponding manner. The pulses of the head KC are amplified by atransistor TR the emitter of which is grounded to the positive terminalof capacitor KB, while the collector is connected through a choke coilSM to the supply point -V. The base is connected through the winding ofthe reading head KC and a resistor RC decoupled by a capacitor KD to thesupply point V. The transistor T2 is included in a generator arrangementhaving a tuned circuit consisting of an inductor LA, of a capacitor KFwhich determines the carrier frequency of the generator and is connectedto the collector of the transistor TZ, and of a feedback winding LBconnected to the base of the transistor TZ. The emitter of thetransistor TZ is connected to ground, while the base is connectedthrough the winding LB and a resistor RD decoupled by a capacitor KE tothe supply point V. A tapping on the winding LA is connected to thecollector of the transistor TR so that the strength of the oscillationproduced by the generator is varied in accordance with the synchronizingsignals supplied by the reading head KC. The windings LA and LB arearranged on the same ferrite rod FS which acts at the same time as atransmitter aerial and transmits the amplitude-modulated signals througha receiving aerial PC to a receiver SC of the testing device shown inFIG. 1. The carrier frequency of the transmitter ZC is, for example, 55kc./s. and the carrier frequency of transmitter ZN which is designed ina corresponding manner is 105 kc./s. The transmitter ZN transmits thesynchronizing signals from the reading head KN through the receivingaerial PN to the receiver SN of the testing device shown in FIG. 1. Inthe embodiment shown, the transmitters are amplitude-modulated. As amatter of course, the latter may also be frequency-modulated.

The identification signal pulses supplied by the receiver SN areapplied, after being limited, to the input of a shift register SR whichis passed to its zero position with each synchronizing pulse through aconductor BA and the delay device VR under the control of thesynchronizing pulses supplied by the receiver SC. The shift register SRreceives on the other hand shift pulses through a conductor BB at theinstants corresponding to the centers of the elements of theidentification code. Under the control of these shift pulses, the binaryinformation in the shift register is moved through one place in knownmanner, while at the same time the binary information corresponding tothe output voltage of the signal receiver SN is recorded in the shiftregister SR at that instant.

Consequently, the elements of the identification code are read atinstants corresponding to the centres of these elements so that in caseof a certain distortion of the pulses, the elements are neverthelessappreciated at their correct values. It is evident that the signallingspeed dependings upon the rotation speed of the motor M, that is to saythat the speed is still low during the start of the motor and theduration of a code element of a code group may be, for example, two orseveral times greater than the nominal rotational speed of the motor.Since, however, it must also be possible to identify carriages whichmove, for example, at a speed of kms. per hour, it is desirable not towait till the motor has reached its nominal speed, but the inforamtionmust be read as soon as possible. In order to permit of indicating thecentres of the various code elements notwithstanding the variablesignalling speed, the testing device is constructed in a particularmanner, that is to say that these instants are derived from the durationof the preceding period between two synchronizing pulses. This ispossible, since the signalling speed between two succeeding code groupsvaries only comparatively slightly, for example less than 10%. To thisend, the testing device comprises a pulse generator GR, the pulsefrequency 1' of which is high with respect to the pulse frequency of thecode signals. On the one hand, the pulses of the generator GR aresupplied to the counting circuit TC and on the other hand to thefrequency divider FD which reduces the frequency by r a factor 10 to 0.1i and which supplies these pulses to the inputs of two gates PA and PBcontrolled in opposite phases by the bistable trigger arrangement FA.The trigger arrangement PA receives through conductor BC synchronizingpulses from the receiver SC and its condition changes with each pulse,so that alter nately during one period between two synchronizing pulsesthe gate PA transmits the output pulses of the frequency divider FD tothe counting circuit TA while the gate PB is cut off, whereas during theother period the gate PB transmits the pulses to the counting circuit TBwhile the gate PA is cut off. At the instant when the gate PA becomesconducting, the trigger arrangement FA supplies, through the conductorBD, a pulse which sets the counter TA in the zero position, whereasconversely, when the gate PB becomes conducting, the counting circuit TBis set in the zero position by a pulse of the trigger arrangement FAthrough the conductor BE. The counting circuits consequently each countalternately during a period between two synchronizing pulses and thenremain in the occupied final position during the following period, whichfinal posi= tron is consequently a measure of the duration of thepreceding period. The coincidence circuits CA and CB respectively, arecontrolled by the trigger arrangement FA so that during the period inwhich the counter TA does not receive pulses, the coincidence circuit CAis operative and compares the occupied final position of the counter TAwith the constantly varying position of the counter TC, while during theperiod in which the counter TB is inoperative, the coincidence circuitCB compares the final position of the counter TB with that of thecounter TC.

The counter TC is set, through the conductor BF and the mixer stage MP,back to the rest position by each synchronizing pulse and consequentlystarts counting from zero. Let it be assumed that at such an instant thecounter TA has occupied a position which characterizes the duration ofthe preceding period, which position is compared by the coincidencecircuit CA with that of the counter TC. Since the frequency of thepulses supplied by the generator GR to the counter TC is ten times thefrequency of the pulses supplied to the counter TA during the precedingperiod, the counter TC will reach a position which corresponds to thefinal position of the counter TA in a period of time equal to 0.1 of theduration of the preceding period between the synchronizing pulses. Whenthe counters have reached .equal positions, the coincidence circuit CAsupplies a pulse through the conductor BG to the trigger arrangement PB,while on the other hand the counter TC is passed back to the restposition by this pulse through the mixer stage MP and starts countingagain until the final position of the counter TA is reached again, andso on. The coincidence circuit CA consequently supplies pulses duringthis period at instants which correspond to 0.1 period, 0.2 period, 0.3period, and so on after the beginning of the period, that is to say atinstants which correspond both to the center of the code elements and tothe end of each code element, while in a corresponding manner, thecoincidence circuit CB supplies pulses during the following period.Pulses are produced at the conductor BG, as shown in FIG. 40. Theincoming signals must be read, however, and the shift pulses must besupplied to the shift register only at the instants which correspond tothe centres of the elements, that is to say after 0.1 period, 0.3period, 0.5 period, and so on. To this end, the trigger arrangement PEis switched through the conductor BF to a given rest state with eachsynchronizing pulse and subsequently, the state of the triggerarrangement FB changes with each pulse of the coincidence circuits CAand CB. Consequently, the trigger arrangement passes each time to theoperating state after 0.1 period, 0.3 period, 0.5 period, and so onafter a synchronizing pulse and supplies a shift pulse through theconductor BB to the shift register SR, as shown in FIG. 4d.

The shift register SR has five outputs which are connected on the onehand to the vertical conductors of a coincidence matrix memory MG and onthe other hand to the coincidence circuit CC. The matrix memory MG isdesigned in known manner and consists of a plurality of memory coresM11, M12, M21 and so on, of magnetic material having a rectangularhysteresis loop, each of these cores being coupled with one verticalcontrol conductor and one horizontal control conductor. The number ofhorizontal conductors is equal to the number of digit groups of thecode. In the embodiment, four horizontal conductors are shown, but inpractice, this number is from 12 to 15. The horizontal condutcors HG HGZand so on are connected to various outputs of a counting circuit TDwhich may receive through the gate PD synchronizing pulses from thereceiver SC and may be set to the following counting position by thesepulses. In the rest position of the circuit arrangement, all the memorycores are in a given remanence state. A core can be passed to theopposite remanence state only when a current flows at the same timethrough the horizontal conductor and the vertical conductor coupled withthis core. In the rest position of the arrangement, however, the gate PEis cut off so that, independently of the position of the shift registerSR, no current can flow through the vertical conductors. A pulse isproduced through a horizontal conductor only at instants when thecounting circuit TD reaches the corresponding counting position. In therest position, the gate PD is cut off and the counting circuit TD doesnot receive counting pulses so that currents will not fiow through thehorizontal conductors of the matrix memory MG either.

As was already stated, the shift register SR is set back to the zeroposition by each synchronizing pulse. Under the control of the shiftpulses the successive elements of the incoming code group are recordedin the shift register, so that at the end of the period, a whole codegroup is recorded. These elements are tested by the coincidence circuitCC. When the starting code group consisting of five mark elements hasbeen received, the coincidence circuit CC responds and supplies a pulsethrough the conductor BH to the bistable trigger arrangement PC, as aresult of which the latter is passed to the operating state. Under thecontrol of the trigger arrangement PC, the gates PE and PD are releaesd.Moreover, a pulse of the coincidence circuit CC sets the countingcircuit TD in the rest position through the conductor BK. The followingsynchronizing pulse sets the shift register SR to the zero position,while the counting circuit TD takes a step, but no pulse is then appliedto one of the horizontal conductors of the matrix memory MG.

During the following period, first the digit code group is recorded inthe shift register SR and with the subsequent synchronizing pulse thecounting circuit TD takes a step while a pulse is applied to the firsthorizontal conductor HGl of the matrix memory so that the first digit isrecorded on a line corresponding to the cores M11, M12, and so on.Moreover, the shift register SR is passed to the zero position by thesynchronizing pulse. In order to ensure that the information is recordedin the matrix memory before it is erased in the shift register, theerasing pulse through the conductor BA is slightly delayed by thedelaying device VR.

In a corresponding manner the other code digits are recorded in thematrix memory MG. Finally, the starting code combination consisting offive mark elements appears again in the shift register, whereupon thecoincidence circuit CC again supplies a pulse and the triggerarrangement PC is set back to the rest condition, as a result of whichthe gates PE and PD are cut off, while at the same time the triggerarrangement FC supplies a pulse through conductor BX to indicate thatthe whole identification code has been received.

By known means (not shown), the information from the matrix memory MG isthen read, as a result of which the cores of this memory are set back tothe rest remanence state.

What is claimed is:

1. A signal identification system including an interrogator, atransmitter and a receiver, said transmitter generating a uniquely codedsignal including a plurality of indicia arranged in consecutive orderand comprising a pulse coded information carrier, said carrier having aplurality of characteristic information pulse code series thereon, eachof said pulse code series but the first indicative of the numericalvalue of a respective one of said indicia, the first of said pulse codeseries constituting a synchronizing code for indicating the beginning ofthe information portion of said series, and a plurality of pulse codegroup marks for indicating the beginning of each of said informationpulse code series, reading means coupled to said carrier means andresponsive to said code representations, motor means activated bywireless energy transmission from said interrogator, said motor meansimparting relative motion between said carrier means and said readingmeans, said reading means converting said series and said marks toelectrical pulses at a rate dependent upon the rate of said relativemotion, and means coupling the electrical pulses produced by saidreading means to said receiver.

2. A signal identification system for transmitting information from amoving object to a spaced receiving location, said informationidentifying the said moving object and including a plurality of indiciaarranged in consecutive order, said system comprising at said movableobject a pulse coded information carrier having a plurality ofcharacteristic information pulse code series thereon, each of saidcharacteristic information pulse code series but the first indicative ofthe numerical value of a respective one of said indicia uniquelyrepresentative of said moving object, the first of said characteristicinformation pulse code series constituting a synchronizing pulse codefor indicating the beginning of the information portion of saidcharacteristic information pulse code series, and a plurality of pulsecode group marks for indicating the beginning of each of saidcharacteristic information pulse code series, reading means coupled tosaid carrier means and responsive to said code representations, motormeans, said motor means imparting relative motion between said carriermeans and said reading means, said reading means converting saidcharacteristic information pulse code series and said pulse code groupmarks to electrical pulses at a rate dependent upon said rate of motion,means coupling said reading means to oscillating means, said readingmeans modulating said oscillating means in accordance with theinformation coded on said carrier and at a rate dependent upon therelative movement of said carrier and said reading means, means couplingthe modulated signal from said oscillating means to said receiver, andwireless energy transmission means remote from said movable object foractivating said motor means and said oscillating means.

3. The combination of claim 2 wherein said reading member includes afirst sensing circuit responsive to said information pulse code seriesand a second sensing circuit responsive to said pulse code group marks,and said oscillating means includes a first oscillator connected to andmodulated by said first circuit and a second oscillator connected to andmodulated by said second circuit.

4. The combination of claim 2 wherein said code carrier consists of adisc of magnetic material having a plurality of informationrepresentative code teeth on the circumference thereof, each of saidteeth being in the shape of a saw-tooth having one straight edge and oneoblique edge movable with respect to an air gap 8 defined by saidreading member in a pre-magnetized magnetic circuit.

5. A signal identification system including a transmitter and receiver,said transmitter generating a uniquely coded signal including aplurality of indicia arranged in consecutive order and comprising apulse coded in formation carrier, said carrier having a plurality ofcharacteristic information pulse code series thereon, each of said pulsecode series indicative of the numerical value of a respective one ofsaid indicia, a plurality of pulse code group marks for indicating thebeginning of each said information pulse code series, the first of saidpulse code series constituting a synchronizing pulse code for indicatingthe beginning of the information portion of said series, reading meanscoupled to said carrier means and responsive to said coderepresentations, motor means, said motor means imparting relative motionbetween said carrier means and said reading means, said reading meansconverting said series and said marks to electrical pulses at a ratedependent upon the rate of said relative motion, means coupling saidreading means to said receiver, said receiver including means fordecoding said pulse code series, and means responsive to saidsynchronizing pulse code for synchronizing said means for decoding tothe rate of said relative motion.

References Cited by the Examiner UNITED STATES PATENTS 1,767,749 6/1930Fisher.

RODNEY D. BENNETT, Acting Primary Examiner.

CHESTER L. IUSTUS, Examiner.

P. M. HINDERSTEIN, Assistant Examiner.

1. A SIGNAL IDENTIFICATION SYSTEM INCLUDING AN INTERROGATOR, ATRANSMITTER AND A RECEIVER, SAID TRANSMITTER GENERATING A UNIQUELY CODEDSIGNAL INCLUDING A PLURALITY OF INDICIA ARRANGED IN CONSECUTIVE ORDERAND COMPRISING A PULSE CODED INFORMATION CARRIER, SAID CARRIER HAVING APLURALITY OF CHARACTERISTIC INFORMATION PULSE CODE SERIES THEREON, EACHOF SAID PULSE CODE SERIES BUT THE FIRST INDICATIVE OF THE NUMERICALVALUE OF A RESPECTIVE ONE OF SAID INDICIA, THE FIRST OF SAID PULSE CODESERIES CONSTITUTING A SYNCHRONIZING CODE FOR INDICATING THE BEGINNING OFTHE INFORMATION PORTION OF SAID SERIES, AND A PLURALITY OF PULSE CODEGROUP MARKS FOR INDICATING THE BEGINNING OF EACH OF SAID INFORMATIONPULSE CODE SERIES, READING MEANS COUPLED TO SAID CARRIER MEANS ANDRESPONSIVE TO SAID CODE REPRESENTATIONS, MOTOR MEANS ACTIVATED BYWIRELESS ENERGY TRANSMISSION FROM SAID INTERROGATOR, SAID MOTOR MEANSIMPARTING RELATIVE MOTION BETWEEN SAID